Benzalkonium chloride is cationic, meaning it carries a positive charge. This makes it alkaline in solution.

Here's why:

* Cationic surfactants like benzalkonium chloride have a positively charged head group.

* Alkaline solutions have a pH greater than 7, indicating a higher concentration of hydroxide ions (OH-) compared to hydrogen ions (H+).

* Cationic surfactants tend to increase the pH of the solution, making it more alkaline.

Important Note: While benzalkonium chloride is alkaline, the actual pH of a solution will depend on the concentration of the benzalkonium chloride.